长江下游莲花洲港大型底栖动物摄食功能群时空分布及其影响因子

2019年8月-2020年1月在长江下游莲花洲港15个采样点进行了6次采样调查,并对该区域大型底栖动物摄食功能群的时空格局及其与环境因子的关系进行了分析。结果显示:调查共采集到大型底栖动物3门40种,其中节肢动物门21种、软体动物门10种、环节动物门9种。莲花洲港的底栖动物由5个摄食功能群构成,其中,撕食者占有较大优势,相对丰度为49.19%,其次为收集者、捕食者、滤食者和刮食者,相对丰度分别为35.05%、10.15%、3.03%、2.58%。单因素方差分析表明,底栖动物密度在不同区域内具有显著差异,在鱼巢排区最高(142.22 ind./m²),透水框架区次之(137.56 ind./m²),其他区域最低(34.22 ind./m²)。鱼巢排区和透水框架区以撕食者占有较大优势,其他区域以收集者占优势。冗余分析(RDA)表明,丰水期和平水期影响大型底栖动物摄食功能群的主要环境因子为水深、水温;枯水期影响大型底栖动物摄食功能群的主要环境因子为水深、溶氧和pH。

Spatial-temporal distribution and the influencing factors of macrozoobenthos functional feeding groups in Lianhuazhou Port,the lower reaches of the Yangtze River

The spatial and temporal patterns of functional groups of macrozoobenthos in this region and their relationship with environmental factors were analyzed based on six sampling surveys at 15 sampling sites in Lianhuazhou Port in the lower reaches of the Yangtze River from August 2019 to January 2020.The results showed that 40 macrozoobenthos species were identified,including 21 species of Arthropoda,10 species of Mollusca and 9 species of Annelida.Overall,these taxa into following five functional feeding groups were categorized,among which the relative abundance was 49.19%,followed by 35.05%,10.15%,3.03%and 2.58%for gather-collectors,predators,filter-collectors and scrapers,respectively.One-way ANOVA analysis showed that the average density of macrozoobenthos was significantly different in different regions.The density of macrozoobenthos was the highest in the fish nest frames areas(142.22 ind./m²),followed by the tetrahedron permeable frames areas(137.56 ind./m²),and lower in other areas(34.22 ind./m²).The areas with fish nest frames and tetrahedron passable frames were dominated by shredders,while collectors dominated the other areas.Redundancy analysis results showed that feeding function groups was determined mainly by the interactions between water depth and water temperature in the wet season and regular season.In the dry season,the primary environmental factors limiting feeding function groups were water depth,dissolved oxygen and pH.